Pairing Django and Titanium in a Desktop App

Over the past four months I have been doing a lot of work in Python and Django. Naturally, while recently playing around with Appcelerator Titanium Desktop (which seems to have good Python support), I wanted to see how Django and Titanium would pair.

Assumptions

What Worked

Over the course of a few hours, I was able to accomplish the following:

Django Template integration
Django ORM interaction
Titanium Database communication with the Django DB (SQLite) defined in settings.py

Directory Layout

Creating the Project

When a Titanium Desktop application (with Python support) is running, the Resources directory for the application is placed in the system Python path. Therefore, my first step was to place the main django directory in Resources. From there, I navigated to Resources and executed the startproject command:

$ django-admin.py startproject test_project

Next, I updated settings.py with information about my test database:

import os
DATABASES ={
    'default':{
        'ENGINE':'django.db.backends.sqlite3',
        'NAME': os.path.join(os.path.dirname(os.path.dirname(__file__)),'test_project.db'),
    }
}

I made sure to include the full path to my test_project.db database, knowing that I would eventually need to refer to this path for Titanium Database support. Finally, I executed my syncdb command from within my test_project directory:

$ ./manage.py syncdb

When prompted, I added a superuser account for myself.

Django Template Integration

Template integration was pretty smooth. What follows is a scaled down version of my index.html resource, and its associated files:

Resources >> index.html

//Yes,this is all I have inmy main index.html resource
<script type="text/python">
    from test_project.contrib.template import index
    document.write(index())
</script>

Resources >> test_project >> contrib >> template.py

def index():
    kwargs ={'foo':'bar'}
    return _render_template('index',**kwargs)

def _render_template(template_name,**kwargs):
    from django.templateimport loader,Context
    t = loader.get_template('%s.html'% template_name)
    c =Context(kwargs)
    return t.render(c)

Resources >> test_project >> templates >> base.html, index.html

{% block py_imports %}{% endblock %} <!DOCTYPE html> <html dir="ltr" lang="en-US"> <head> <title>{% block title %}{% endblock %}|TitaniumTesting</title> <script type="text/javascript" src="jquery-1.3.2.js"></script> {% block js %}{% endblock %} </head> <body> {% block content %}{% endblock %} </body> </html>

# index.html {%extends"base.html"%} {% block title %}TemplateCommunication{{ block.super}}{% endblock %} {% block content %} <strong>Foo</strong>:{{ foo }} {% endblock %}

Database Communication

Database communication also went fairly smooth (though I did get tripped up trying to find a method to use an existing SQLite db for Titanium … ultimately the following worked for me:

Titanium.Database.openFile('/path/to/db'))

What follows are the code snippets which represent successful communication with the DB via Django, and via the Titanium Database API:

Resources >> test_project >> contrib >> db.py, user.py

# user.py def py_update_name(username, first_name, last_name): from django.contrib.auth.models importUser user =User.objects.get(username=username) user.first_name = first_name user.last_name = last_name user.save() def py_get_full_name(username): from django.contrib.auth.models importUser user =User.objects.get(username=username) return user.get_full_name()

Resources >> test_project >> templates >> index.html (full version)

{%extends"base.html"%} {% block title %}DatabaseCommunication{{ block.super}}{% endblock %} {% block py_imports %} <script type="text/python"> from test_project.contrib.user import py_update_name, py_get_full_name from test_project.contrib.db import py_get_db </script> {% endblock %} {% block js %} <script> var username = 'leveille'; var first_name = 'Jason' var last_name = 'Leveille' /** *TellDjango to update user first/last name */ py_update_name(username, first_name, last_name); $(document).ready(function(){ /** *UseDjango to query the auth database *andreturn the user fullname */ var $test_1 = $('#test_1'); $('button', $test_1).bind('click', function(){ $('.result', $test_1).text(py_get_full_name(username)); }); var $test_2 = $('#test_2'); $('button', $test_2).bind('click', function(){ var val = 'Empty result set'; try { var db = Titanium.Database.openFile(py_get_db()); var rs = db.execute( "SELECT first_name, last_name FROM auth_user " + "WHERE username = '" + username + "'" ); if(rs.isValidRow()){ val = rs.field(0) + ' ' + rs.field(1); } } catch (err) { val = err; } finally { rs.close(); db.close(); $('.result', $test_2).text(val); } }); }); </script> {% endblock %} {% block content %} <div id="test_1"> <h1>Test1</h1> <p> <button>Django Query for my Full Name</button> </p> <p> <strong>Result</strong>: </p> </div> <div id="test_2"> <h1>Test2</h1> <p> <button>Titanium Query for my Full Name</button> </p> <p> <strong>Result</strong>: </p> </div> <div id="test_3"> <h1>Test3</h1> <p> Passing Template Variables </p> <p> <strong>Foo</strong>: {{ foo }} </p> </div> {% endblock %}

The Result

If you have experience playing around with these two playfellows, feel free to share them here.

Jason Leveille

Web developer, loving life in Southern Maine